site-to-site vpns are an alternative wan infrastructure that replace and augment existing private networks using leased lines, frame relay, or atm to connect remote and branch offices and central site(s). for site-to-site vpns, the pix firewall can interoperate with any cisco vpn-enabled network device, such as a cisco vpn router.

    site-to-site vpns are established between the pix firewall and a remote ipsec security gateway. the remote ipsec security gateway can be a pix firewall, a cisco vpn concentrator or vpn-enabled router,or any ipsec-compliant third-party device. for configuration instructions, refer to "basic vpn configuration," and for example configurations, refer to "site-to-site vpn configuration examples."